| Keyword | Use |
| abstract | Specifies that a class or method will be implemented later, in a subclass |
| assert | Assert describes a predicate placed in a Java program to indicate that the developer thinks that the predicate is always true at that place. |
| boolean | A data type that can hold True and False values only |
| break | A control statement for breaking out of loops. |
| byte | A data type that can hold 8-bit data values |
| case | Used in switch statements to mark blocks of text |
| catch | Catches exceptions generated by try statements |
| char | A data type that can hold unsigned 16-bit Unicode characters |
| class | Declares a new class |
| continue | Sends control back outside a loop |
| default | Specifies the default block of code in a switch statement |
| do | Starts a do-while loop |
| double | A data type that can hold 64-bit floating-point numbers |
| else | Indicates alternative branches in an if statement |
| enum | A Java keyword is used to declare an enumerated type. Enumerations extend the base class. |
| extends | Indicates that a class is derived from another class or interface |
| final | Indicates that a variable holds a constant value or that a method will not be overridden |
| finally | Indicates a block of code in a try-catch structure that will always be executed |
| float | A data type that holds a 32-bit floating-point number |
| for | Used to start a for loop |
| if | Tests a true/false expression and branches accordingly |
| implements | Specifies that a class implements an interface |
| import | References other classes |
| instanceof | Indicates whether an object is an instance of a specific class or implements an interface |
| int | A data type that can hold a 32-bit signed integer |
| interface | Declares an interface |
| long | A data type that holds a 64-bit integer |
| native | Specifies that a method is implemented with native (platform-specific) code |
| new | Creates new objects |
| null | This indicates that a reference does not refer to anything |
| package | Declares a Java package |
| private | An access specifier indicating that a method or variable may be accessed only in the class it’s declared in |
| protected | An access specifier indicating that a method or variable may only be accessed in the class it’s declared in (or a subclass of the class it’s declared in or other classes in the same package) |
| public | An access specifier used for classes, interfaces, methods, and variables indicating that an item is accessible throughout the application (or where the class that defines it is accessible) |
| return | Sends control and possibly a return value back from a called method |
| short | A data type that can hold a 16-bit integer |
| static | Indicates that a variable or method is a class method (rather than being limited to one particular object) |
| strictfp | A Java keyword is used to restrict the precision and rounding of floating-point calculations to ensure portability. |
| super | Refers to a class’s base class (used in a method or class constructor) |
| switch | A statement that executes code based on a test value |
| synchronized | Specifies critical sections or methods in multithreaded code |
| this | Refers to the current object in a method or constructor |
| throw | Creates an exception |
| throws | Indicates what exceptions may be thrown by a method |
| transient | Specifies that a variable is not part of an object’s persistent state |
| try | Starts a block of code that will be tested for exceptions |
| void | Specifies that a method does not have a return value |
| volatile | This indicates that a variable may change asynchronously |
| while | Starts a while loop |
